Restrictive Covenants

Restrictive covenants are put into a deed by the seller of the property.  Often when it's a new development, they're put in there by the developer.  They're a private agreement, and won't be enforced by the local government.  To enforce them, sometimes every single neighbor in the development must join in the complaint.  Sometimes a covenant is worded so that it will expire after a certain length of time.  Sometimes a neighbor or other concerned person can go to court and ask that the restriction be enforced, but the courts are usually more sympathetic with the homeowner who wants to violate a deed restriction. 

All old deed restrictions that forbid re-sale to a member of a class protected by fair housing laws are unenforceable. 

Hope this helps.